my heart rate was tested at 40bpm when i boxed.as a distance runner up till 2004 it was 35bpm and i was no fitter than anybody else
My resting heart rate is at 48 bpm. I'm in decent shape but nothing spectacular. It's been as low as 42 before but I ran a lot more back then.
35 beats per minute puts you in phenomenal shape category. Both those guys I cited are world champions.
It's not quite as simple as that. If it gets down to 0, your probably not going to be performing at your best...